The present invention generally relates to detecting unauthorized entry into a secure area and, more particularly, to a system and method for detecting doorway tailgating.
It is common for buildings and other structures to have restricted access areas (also called secure areas) that can only be entered and exited by controlled access points, such as locked doors, turnstiles, etc. Admittance of a person through a controlled access point is often automated through access control systems that utilize an RFID reader at the controlled access point and access cards (e.g., badges) that have a radio frequency identification (RFID) tags. Authorized persons are issued an access card having a unique RFID tag, and the system electronically unlocks a door or turnstile at the controlled access point when the RFID reader detects the presence of an RFID tag of an authorized person. In this manner, the controlled access point may remain normally locked to prevent access of unauthorized persons, and may be temporarily unlocked when presented with an RFID tag of an authorized person.
One of the biggest weaknesses of automated access control systems is the fact that most systems cannot actually control how many people enter a controlled access point when an access card is presented. For example, most systems allow you to control which card works at a particular controlled access door, but once an employee opens the door with their authorized access card, any number of people can follow behind the employee and enter into the building. Similarly, when an employee exits the building, it is very easy for a person to grab the open door and enter the building as the employee is leaving. These practices are referred to as “tailgating” which generally refers to one or more persons gaining access through a controlled access point by following another person through the access point and without presenting an access card. Other examples of tailgating include an employee opening a door and holding it open for others, visitors without badges, or the passive acceptance of a uniformed worker.
Types of technologies that are currently used to detect tailgating include: smart cards that house multiple credentials on one card; security guards that can visually confirm a badge matches the holder; turnstiles that serve as a physical barrier and are good for high-volume traffic; laser sensors that can detect multiple people; biometrics that deter employees from sharing credentials; long-range readers that can be used in parking lots and garages; PIN numbers that can be added to card readers; camera analytics that enable remote facial recognition; visitor badges that ensure temporary guests are documented; and traps or air locks that require a double set of identification.